Ductile crack formation on notched Al2024-T351 bars under compression–tension loading

A study on crack formation under compression–tension reverse loading was carried out both experimentally and numerically. It was found that pre-compression plays a very important role in crack formation. The dimple structure observed from fracture surface is finer and the size of voids is smaller in the case with pre-compression than the case without pre-compression. Particles crack along the loading direction under pre-compression loading, while particles fail in the direction perpendicular to the loading direction under tensile loading. The criterion developed for monotonic loadings was unable to predict crack formation in the present compression–tension reverse loading. A new fracture model was developed and good predictions were obtained.